S-lang/ISIS Timing Analysis Routines (SITAR) Home Page

SITAR, S-lang/ISIS Timing Analysis Routines, presents a set of functions and subroutines designed to be run within ISIS in order to perform timing analysis of data. The specific examples presented here relate to data obtained with the Chandra X-ray Satellite or with the Rossi X-ray Timing Explorer-All Sky Monitor (RXTE-ASM).

The subroutines are written in S-Lang, with reliance on functions intrinsic to ISIS. A few features rely on the use of the GNU Scientific Library module available from the S-Lang Modules Packages. (Specifically, the Gregory-Loredo algorithm, certain options for the Bayesian Blocks routine, and the proper statistical significances of epoch fold values rely on the use of GSL.)

Currently, SITAR provides a set of routines for:

• Performing a Bayesian Blocks decomposition of a lightcurve, based upon an algorithm and MATLAB codes developed by Jeffrey Scargle.
• Evenly dividing a lightcurve using the Bayesian algorithm of Gregory & Loredo.
• Reading RXTE-ASM lightcurves
• Rebinning rate lightcurves, and rebinning power spectra
• Period and epoch-folding rate lightcurves
• Period folding event lightcurves
• Power and Cross Power Spectral Density functions

   isis> y = sitar_pfold_rate(t,rate,2.e4,,,50,3.5e8);

   isis> y = sitar_pfold_rate(t,rate,2.e4;nphs=50,tzero-3.5e8);

   isis> y = sitar_pfold_rate(t,rate,2.e4;tzero-3.5e8,nphs=50);